Without an Alibi
by magentacr
Summary: 3 parter, based on the song 'Over the Hills and Far Away'. Mary and Sherlock have always been a bit flirty, but how far will they go to protect John from the truth when things go further than flirting, and will he be able to forgive them when he finds out?
1. You Stand Accused

_Disclaimer - I do not own anything that is already owned by ACD or BBC including characters/places etc._

_AN: Okay so firstly I suppose I should mention a trigger warning for adultery. This story was inspired by the song 'Over the Hills and Far Away' by Gary Moore/Nightwish (check the song out if you havent heard it before) which I found a fantastic story concept that I felt was perfect for the Sherlock universe, even if the concept may be considered slightly OOC, though I've tried to make the rest of it as in character as possible to make up._

_Also I realize Sherlock/Mary may not be a very popular ship for storys, but I wouldn't say this story really is that, it's totally John and Mary, it only touches on Sherlock and Mary for the sake of story concept. So really what I'm saying is I hope you give this story a chance even if it isn't your normal taste._

_So without further ado, before I give away any more plot spoilers;_

**Chapter 1 – You Stand Accused**

Sherlock knew immediately when he woke that he wasn't in his bed. The sheets were a cheaper make, almost itchy against his skin compared to the Egyptian cotton he usually slept in. The alarm was another sure sign; he never set an alarm. And last but not least, the groan and jostling of bed springs as someone rolled over and slapped at the alarm to stop it. His eyes opened at the same time as his bedmate gasped, and the memories from the previous night came flooding over him.

He had gone to the Watson's house looking for John, ready to tell him the fascinating results of one of his latest experiments. But John was away at some kind of medical conference, apparently he had told Sherlock, but he didn't remember. Anyway, Mary had invited him in, to visit their daughter, and for a chat, and insisted on giving him dinner as well. Somewhere along the line as they talked, a bottle of wine had been consumed, one thing led to another, and now here they were, in her bed -Her and John's bed- the morning after, feeling terrible for what they had done.

"We don't tell John about this." Mary told him, getting dressed with her back to him as he did likewise. At his silence she looked round slightly and added "I mean it Sherlock, this was a mistake but it won't happen again so John doesn't need to know. I know you like to be liberal with the truth, but I swear if you tell him and I lose him I will kill you properly this time."

"If John finds out you won't have a chance to kill me, he'll do it himself." Sherlock answered stonily.

"No he won't. John will forgive you, he always does. Me... I'm on my last chance." Mary answered sadly.

"I wouldn't be too sure of that. John is a fairly open minded guy, I'm sure if you explained to him-"

"Not about things like this. You remember how he reacted to people thinking you two were a couple. When it comes to love and marriage, he's pretty straight-laced" Mary asserted, now sitting at the vanity table running a brush aggressively through her short locks.

"He's fine with homosexuals and other unusual arrangements, he told me so the first day he met me." Sherlock insisted.

"He's happy for others to do that, but it's not what he wants for himself. Trust me, he won't take this well. Promise me, Sherlock, promise you won't tell him. You won't tell anyone." Mary stood back up and faced him.

"I won't tell. But I still think you should." Sherlock said, before turning and walking briskly out the room.

"Probably best not even to mention you were here. You're hardly the type to pop round for a social call, are you? No need to make John suspicious." Mary followed him out, leaning against the hallway wall as Sherlock donned his coat and scarf.

"I do have social calls, with you and John and... Charlotte." Sherlock defended.

"Only when we come to Baker Street, never here." Mary shook her head "You only come here to grab John for cases. Even when we invite you to dinner in advance you never come, you make some excuse."

"Fair point." Sherlock conceded. "Then I was never here."

And with that he swept out the house.

There was a police car waiting outside 221b when he arrived, and when he peeked up at the second floor window he saw a flash of silvery hair pulling away. Lestrade was waiting for him, and unusually anxious.

"Where've you been, freak?" Sally Donovan coldly greeted him the second he'd gotten into the flat. She had been remorseful for her part in destroying his reputation and fairly nice to him when he first came back, but time was rapidly undoing that, and she was almost completely back to her old self now.

"I don't believe that's any of your business." Sherlock returned, flopping down in his usual chair, nonchalant.

"Actually, it might be." Lestrade said, already sounding remorseful for whatever bad news he bore. "There was a murder last night, Sam Green, a 20 year old uni student. He was bludgeoned to death with a baseball bat outside of his local at about 2 o'clock this morning for no apparent reason." He paused and took a big breath "Your prints are all over the scene and from what the CCTV caught of the attack, the perp did bear a resemblance to yourself and that big coat of yours. Now I'm perfectly ready to believe you didn't do it, and get you on the case to figure out who did, but I'm gonna need to know where you were last night, and if anyone can confirm it."

"My alibi you mean." Sherlock replied, looking up at the DI he called a friend. So ready to believe the best of Sherlock, even if Sally behind him didn't look so sure. Sherlock couldn't help but wonder what he would think if he knew what Sherlock had really done the night before? He'd be disappointed for sure, probably stress over it, even if it wasn't his problem; that was just what he did. Obviously it would make him think of his own wife's infidelity. But would that motivate him to tell John, or leave it be? He certainly tended to prefer the bliss of ignorance where possible in his own case, but that didn't mean he thought it best for others. No, best not to tell. Mary probably wouldn't confirm it for him anyway.

"Sorry, can't help you there." He answered without missing a beat.

Lestrade closed his eyes on a deep sigh, rubbing his hand down his face in stress and exhaustion.

"I was hoping you wouldn't say that. Look, if it's drugs-"

"Do I look like I'm coming down from a high, to you?" Sherlock answered sharply.

Lestrade had seen Sherlock strung out on drugs far too many times in years gone by, and had to admit that Sherlock definitely didn't look as he had then, he looked clean.

"No, no you don't" he admitted, defeated, "Look, Sherlock, I'm trying to help you here, but with all the proof against you, and without an alibi, I've not got much choice, I'll have to bring you in."

Sherlock stood slowly, until he was toe to toe with Lestrade.

"Are you sure you want to do that, Detective Inspector? You remember what happened last time?"

Oh did he remember. The sleepless nights thinking his friend had killed himself over his betrayal, tirelessly working to prove Sherlock wasn't a fraud, and even when he did there was still the letters, more of them even, from Sherlock's supporters accusing the Yard of responsibility for Sherlock's suicide.

"Yeah well, that's why it's just the two of us this time, no rookies for you to steal a gun from." Sally responded in the pause, remembering things differently.

Sherlock's eyes remained on Lestrade's, until the DI could stand it no longer and had to look away.

"Cuff him, Sally."

Just as before, Sherlock didn't resist as Sergeant Donovan cuffed his wrists behind his back, a rougher and a little tighter than strictly necessary. Lestrade read him his rights, still unable to look him in the eye, and led the way out of the apartment and back down the stairs.

"Sherlock? What's going on?" Mrs Hudson asked fearfully, emerging from her flat as they reached the bottom floor.

"Not to worry Mrs Hudson, just a little misunderstanding. I'll make sure the rent still gets paid in my absence." Sherlock reassured her as light-heartedly as possible.

"It's not the rent I'm worried about." she huffed, pushing in front of Lestrade "And you, I thought we were past all this, you know as well as I do that Sherlock is nothing but a good man. Even if he is a bit rough around the edges."

"I'm sorry Mrs H. I really am." Lestrade said earnestly, slipping past her and out the door. Sherlock gave her another reassuring smile, and allowed her to hug him, before following Lestrade out to the car, followed by a silent but slightly uncomfortable Donovan.


	2. Visiting hours

**Chapter 2 – Visiting Hours**

The ride to the station was silent, and besides carrying out the booking in procedure, Lestrade seemed reluctant to break the silence, but eventually of course had to.  
"Alright, you know the procedure probably as well as I do. Do you have a lawyer or anyone you'd like to ring before they pull you in for questioning?"  
Sherlock raised an eyebrow in questioning and then lowered it. "Oh of course, they won't let you question me because you're too close to the subject. Not that there is much point in questioning me, we both know the answers; No I didn't do it, and Yes I probably could prove it, but not the way you want me to."  
Lestrade couldn't help but smile a little at that, despite the situation. "Sounds like you don't need a lawyer, knowing it all already."  
"Obviously. Oh but I will take the phone call though."  
Lestrade grimaced slightly.  
"Technically the phone call allowance is only to contact legal representation."  
"I'd say being the British Government makes Mycroft 'legal representation', don't you?"  
"Well then, go right ahead." Lestrade said, gesturing to the phone on the wall and taking a few steps back to give him a little privacy.  
Sherlock nodded and took up the phone, leaning against the wall as he held it to his ear and dialled. His brother answered on the 3rd ring, as ever.  
"You never phone if you can avoid it. What's happened?"  
"Well you know prisons, still stuck in the 20th century with their one phone call policy."  
Sherlock could practically hear his brother rolling his eyes the other side of the phone. "Sherlock." He groaned in exasperation. "What did you do this time?"  
"Not what they think I did. Unfortunately I find myself without a viable alibi." Sherlock informed him.  
"I see. I'll review the security footage you appear in, see if I can assemble a timeline for-"  
"That's not what I'm asking" Sherlock cut him off, glancing over his shoulder to make sure Lestrade had kept his distance, and lowering his voice. "I want you to erase any information regarding where I was last night."  
"Sherlock? Are you asking me to cover up a crime for you?"  
"Technically not a crime, just something I'd rather not come out."  
"Hmm." Mycroft replied, and Sherlock could almost picture him poring over the file Anthea had no doubt just placed in front of him, efficient as she was. He would know any second, but Sherlock knew he could count on his discretion, and of course censure. "Oh Sherlock. Of all the women and all the days. What will John say I wonder?"  
"Don't you dare Mycroft! I'm trusting you to ensure he doesn't find out. Through the wrong means at least; if she chooses to tell him that's her choice, and you will not take that from her." Sherlock spat, beginning to regret his decision to involve his brother. But if he hadn't, he was sure Lestrade would have at some point.  
"I was just referring to your pending prison sentence." Mycroft answered with mock innocence. "What will you tell him when he asks?"  
"I'll deal with that when it comes to it. All you need to concern yourself with is the deletion of those files. Now if you'll excuse me I believe there's a cell waiting for me." He went to hang up the phone but his brother's voice called him back.  
"Sherlock. Before you go; does Mary know of your current predicament? You said it would be her choice to tell John, but are you allowing her to make an informed decision? She does seem to care for you somewhat, do you really believe she'd abandon you to prison?"  
Sherlock hesitated a second, his hand subconsciously shifting to the still pink scar of the bullet wound on his stomach.  
"I believe she'd do anything to protect her relationship with John. She may care for me 'somewhat' but she cares for him far more. Now if that's all..." He hung up the phone with no hesitation this time, and turned back to Lestrade, who leaning against the wall playing on his phone had apparently heard nothing, or nothing of significance at any rate.  
"Any good? He gonna come down here and sort it all out for you?" He asked hopefully.  
"I wouldn't count on it." Sherlock replied, falling into step with Lestrade again as he led him further down the corridor and into a bland, uniform looking cell.  
"But he's your brother! Surely he must care that-"  
"'Caring' is something Mycroft tries not to do." Sherlock reminded him.  
"Well yeah, but you can't tell me he doesn't care about you, I've seen it too many times not to believe it." Lestrade stood his ground.  
"Perhaps. And that's why he's doing what I've asked of him, and nothing more."  
Lestrade shook his head, turning to leave, and lock the cell behind him. "I never will understand you Holmes brothers."  
Time moved slowly in the prison cell, even with his brief questioning breaking it up. Boredom threatened to tear his mind apart, making sleep elusive. So he disappeared into his mind palace for the night. They hadn't given him a lot of information about the murder he had supposedly committed, but he sorted through the facts he did know, drawing a few conclusions, but nothing that would be a strong enough support for his case, and nothing that could solve the real one without more data. It was a dead end.  
He tried to avoid thinking about what had happened with Mary, but the night was long, so it was inevitable. There had always been a small spark between them, nowhere near as strong as the one between her and John, but it was there. She was smart, daring, and read him like a book, while still managing to keep her own secrets. He'd stumbled on that combination only once before and it had tempted him then. But under normal circumstances, Sherlock would never have acted on his interest, even if she weren't married. It was the wine that was their downfall. Surprisingly potent, even after a good meal, it had lowered their inhibitions just enough for them to make a mistake. Even now he wasn't sure who had really started it; had she turned their banter into flirting, or had he misread her friendly nature and taken the step further? Did it really matter when they'd both been willing participants in the end?  
He was so deep in his mind, replaying the earlier part of the evening to see where things went wrong, that he didn't hear his cell being unlocked and anyone coming in until they spoke.  
"Sherlock?"  
John's voice was certainly enough to startle him out of his mind palace, sitting bolt upright on the cot and staring at him with wide eyes.  
"John! What are you doing here? I um... Thought you were away. Doctory stuff."  
"I was coming back today anyway, but got the first train when Greg called." John explained, looking at his friend with concern, while Lestrade nodded behind him.  
"Ah, yes of course. Lestrade. How is the case coming?" He inquired, trying to buy himself time to get his head together, or at least away from his previous thought pattern before facing his friend.  
"What case?" Greg shrugged bitterly "They have your prints, a CCTV match and you don't even have an alibi. As far as the Yard is concerned that's case closed, just waiting for a trial date. I haven't the authorisation to investigate further, that's why this is where you'd come in if you weren't in a cell. If you'd just tell us where you were-"  
"Sorry." Sherlock cut off his ranting, sitting up and leaning back against the wall.  
Lestrade angrily turned away, giving John a this-is-what-I've-been-dealing-with look before letting himself out and leaving John alone with Sherlock.  
John's jaw set in resolve, and he marched forward, grabbing Sherlock's wrist in a firm grip and yanking his sleeve up, checking his arm for fresh marks. When he found none, he checked the other arm, a little gentler this time, then examined Sherlock's eyes. Sherlock remained passive until he was done, then asked coldly "Satisfied, Doctor?"  
"That you're clean, yes, but that's not the real issue is it?" He sighed, seating himself beside Sherlock on the bench, "So what's going on, Sherlock? What were you doing on Friday night that you can't tell the police? I don't believe it's that there is simply no-one to confirm it, Mycroft has pretty much all the surveillance in the country at his command, he could back up your location at the very least." He paused, waiting for Sherlock to fill him in, and was surprised to find Sherlock silent, looking determinedly away from him.  
"Sherlock?" He tried again, seriously concerned now "Come on, you know you can tell me anything? I know I may not have handled the whole drugs thing to well in the past, but this is different... You're on murder charges Sherlock, that's, what, 10 years minimum, for a crime you didn't even commit? What could be worth that?"  
Again, Sherlock didn't answer, and John felt a pit of dread settle in his stomach. Sherlock had shot Magnussen in front of at least a dozen witnesses, a SWAT team no less. When he was set on a course of action, he didn't care who knew and what they thought of it. For him to suddenly care, worried John more than anything else could.  
"Okay, so you really don't want the police to know, fine. But could you at least tell me? I'm your best friend, and I've... Done regrettable things myself and withstood everything you've thrown my way so far. And I am seriously worried about you right now, and just want, no, need to know what's going on with you, and if there is anything, anything I can do to help."  
"I think you should go." Sherlock finally reacted, still not looking at John, and if the thickness of his voice was anything to go by, fighting back tears.  
John jumped out of his seat, turning to face Sherlock and holding up his hands in a peaceable gesture. Sherlock's request broke his heart, but he wasn't ready to give up on him yet.  
"Okay, okay, I'll stop asking, but please... Let's just... Let's think of another way to get you out of this mess, eh? If we can't prove it wasn't you who did it, we'll just have to prove who did, right? I mean you must have some idea where to start. And I'll be your eyes and ears to the outside world, it'll be just like those cases where you couldn't be bothered to leave the flat, but without skype."  
Sherlock let himself face John now, his face it's usual emotionless mask, yet 1000 emotions seemed to flicker behind his eyes. Finally they set on resolve, the twinkle of a case to solve coming back into them, as a small smile crept up his cheek.  
"Fingerprints." He stated, a clue and challenge for John.  
"Fingerprints" he echoed "They said they found your fingerprints on the scene."  
"Yes, but they didn't say what they didn't find."  
"Aaaand you've lost me already."  
Sherlock rolled his eyes in annoyance, a good sign that he was back in the game.  
"They said they found my fingerprints, but they didn't say if they found both sets. If someone else is using my fingerprints to commit crimes, they must have lifted them somehow, most likely from a glass, either stolen from Baker Street or a cafe I visited, most likely Baker Street, as it's be less likely to have contamination from other prints, but either way, that would only give them one set of prints."  
"So?"  
"So, the victim was bludgeoned to death with a baseball bat. If you was going to kill someone with a baseball bat, how would you hold it?"  
John shifted his stance, his hands subconsciously shifting as he pictured it in his mind. "With two hands." He said cottoning on.  
"Precisely, maximise the force of the swing. If the prints implicate me in the crime they'd have to be on the bat, and if the perp put them there it would only be one set, he could have fashioned a glove with my prints that he wore on his right hand, and a normal glove on his left to avoid leaving his prints as well." Sherlock explained.  
"That's fantastic, so we just need to tell Lestrade about the prints, he'll check the evidence and you'll be home free." John concluded, but Sherlock shook his head.  
"Oh John, as if it were that simple. You think I wouldn't have told them already if that were the case? Missing prints is not enough to prove my innocence, plenty of crime scenes don't have complete sets of prints; as long as there are a few it's enough. No, we need to find the person, and preferably the glove he used to leave my prints."  
"Yeah about that, how does someone make a glove of your fingerprints anyway? A bit sci-fi isn't it?" John pointed out.  
"Oh yes, but entirely possible." Sherlock replied "They'd just need to create the mould of my prints then cast it in some kind of flesh imitating gel or wax, then attach the products to the glove. That means whoever it was must have some kind of engineering or design background to make the mould in the first place, that narrows the field a little, and then there is their apparent grudge against me. Either Lestrade or Mycroft should be able to give you access to the records of those paroled or released from prison in the last 6 months, and those I helped put there. Start there and see if any of them match the profile."  
"Right, I'll do that." John nodded, a little relieved to have something to do that could help Sherlock. "You just wait here, and I'll take care of it."  
"Well I'm certainly not going anywhere." Sherlock smirked back, making John laugh a little as he made his way hesitantly out the cell, as though reluctant to leave his friend behind. Sherlock kept smiling until his friend disappeared, then the mask dropped into a grim expression, leaning forward on his knees and hanging his head in shame. John's concern for him had been almost more than he could bear, he'd prefer it if John had shouted at him, maybe even hurt him as he probably deserved.  
Only a few minutes later he heard footsteps approaching his cell, and the door opened. Mary stepped meekly into the room, thanking one of Lestrade's young officers who had let her in. They both waited until the door closed again, before Sherlock spoke up.  
"Does John know you are here?"  
"I saw him in the lobby, he's talking to Lestrade. He text this morning saying he was coming straight here from the train station, and why. I left Charlotte at The neighbours and came straight down. Sherlock I... If I'd known, I would never had asked-"  
"I know." Sherlock looked her straight in the eyes.  
"Thank you." She almost whispered, tears glistening in her eyes. Sherlock simply nodded, and Mary tried to pull herself back together. "You'll get out of this, I'm sure. John is pretty determined to find the guy himself, and I'll do what I can. And if worst comes to worst we can always break you out of jail." She attempted to joke, though the smile didn't reach her eyes.  
"And then what?" Sherlock returned her humourless smile.  
"Go on the run I suppose."  
"You know that's not what I mean." He chided her gently. "What about us? You, me and John."  
"We carry on, as we did before. As friends." She shrugged.  
"Do you really believe our friendship can survive this?" He asked earnestly.  
"I don't know, I hope so. I don't want to lose either of you, and I never meant to come between you and John. I guess I've made quite a mess of things." She admitted looking down at the ground.  
"No. We have." Sherlock corrected. Her eyes rose to his again, and she nodded once, before turning to leave.


	3. Occam's Razor

**Chapter 3 – Occam's Razor**

John hadn't stayed long to talk to Lestrade, since he couldn't help him with the ex-prisoner list. Since he didn't know how long Mary would want to spend with Sherlock he left the car for her and grabbed a taxi to take him home, phoning Mycroft on the way to see if he could help. Sure enough he promised to have the list in John's inbox by the time he got home, leaving John to sit back and contemplate Sherlock's behaviour for the rest of the journey. He seemed to be in a better mood when John left to when he arrived, but that didn't completely dispel the unease John felt over Sherlock's reluctance to tell him what had happened Friday night. He knew he wasn't being egotistical to say he was Sherlock's closest and most trusted friend, even if he had waited 2 years to tell him he was still alive after his fall. John had later found out from Molly that he'd only been trying to protect him. Could that be the reason now? But what was he trying to protect him from, and why would he think the best way to do that was from inside a cell? Surely if John and his family were under threat, Sherlock would want to be out there tracking down and eliminating that threat. Unless the threat was that they'd be harmed if Sherlock didn't let himself be arrested, but that sounded far too tame for a master criminal.

No, the threat theory didn't fit, so what else could it be for him not to tell John? Perhaps he felt whatever it was, was a betrayal of John in some way? But how could he possibly have betrayed John, except for putting his family in danger, which John had already decided wasn't an option? Were Sherlock any other man the first thing that would come to mind for a betrayal would be making a move on his wife, but that just didn't sound right either, Sherlock never showed any interest in any woman.

But then Mary wasn't just any woman.

Dismissing the idea as unlikely, John put his theorising to rest as the cab pulled up outside his house, and he paid the driver and got out. He was just unlocking the door when he noticed something unusual.

In the plastic tub outside where they kept the empty bottles waiting for recycling, was the bottle from the Barbito Single Harvest Madeira wine that one of his patients had given him earlier in the week. They had been planning to drink it on Sunday with their roast dinner, but it seemed someone had already beaten him to it. Mary hadn't mentioned having anyone over while he was away, but she never drank alone. Storing the fact away to ask her about later, John continued letting himself in, taking off his coat and shoes and heading for his computer. He couldn't help but glance at the wine rack in the kitchen as he passed the door, and sure enough, there was a bottle of the same wine in the rack. Replacing the wine in apology for drinking it without him, or covering up that it had been drank? He let himself be pulled into the kitchen, opening up the dishwasher. It had been put on last night and was waiting to be emptied, but there was no wine glasses inside. He moved on to the cupboard and sure enough all the glasses were in there, but the front two were noticeably dull and streaky compared to the others; the way they went when John had once hand washed them for fear they'd break in the dishwasher, only to put them in the dishwasher afterwards anyway because they were still so dirty looking. Why would Mary hand wash the glasses when she was going to put the dishwasher on? Unless she was tidying them away in a hurry to hide them.

Suddenly his theory about Sherlock's behaviour being to do with his wife seemed slightly less unlikely.

Heart hammering, John followed his deductions to the bedroom, beginning to hope he was wrong. Opening his bedroom door felt like being back in Afghanistan, about to sweep an unknown room for hostiles. The door swung back to reveal a perfectly unthreatening and tidy room. But it was too tidy. The bed sheets had been changed 2 days early and moving further into the room he saw that the bin had been emptied earlier than usual as well. That left only one place left to check; the wheelie bin.

Usually he would baulk at digging through someone else's rubbish on a case with Sherlock, but this was his rubbish and he simply had to know. In the end he didn't even have to dig through; the contents of the bin had just been tipped in on top of the other bin bags, and there, quite clearly at the top was a used condom and wrapper.

A wave of nausea threatened to overcome John, as reality crashed down on him. Yes it was possible that some teenagers had used their bin after a drunken public quickie, but that didn't happen much round this area. And then there was the condom packet; the same brand that he and Mary had been using before she got the implant, some of which he knew were still hanging about in the house.

As much as he'd like to disbelieve it, all the evidence pointed to the fact Mary, his wife and mother of his daughter, had cheated on him. The question was, was it with Sherlock, or had Sherlock simply discovered her with someone else Friday night and been threatened into silence? Goodness knows she was capable of that.

John slowly unclenched his fists, pushing the surging anger back to focus. His control over his emotions would never rival Sherlock's, but Afghanistan had taught him some. Do what needed to be done first, then deal with the emotions after. Repeating this to himself like a mantra he headed back into the house, left a note for Mary simply saying he had gone out, and came back with a latex glove from his medical kit and nappy bag. He carefully plucked the condom from the bin, bagged it and binned the glove, before taking off down the road to the main road where he could flag a taxi to Barts, hoping that Molly was in today.

Thankfully she was, and he even managed to catch her between autopsies.

"Oh, hello John," she said brightly as ever "No Sherlock today?"

"Um no, he's... Unavailable right now." John skirted.

"What can I do for you today then? If it's about the ears, I'm sorry you wasted a trip but I already told Sherlock no." Molly chatted away, bustling around the morgue cleaning up from her last 'patient'.

"Um no, it's not ears it's um…" He held up the bag with the condom in it. "DNA testing."

To Molly's credit, she didn't bat an eyelid at the contents of the bag. "How old?" She asked.

"Between 24 to 48 hours." John guessed, trying to be as clinical as she.

"Oh, probably still some live ones then, should make it easier." Molly said cheerfully, snapping on some gloves. "Is it just the male you wanted to identify?"

"Both, if possible."

"Well no guarantees, but I'll see what I can do. It'll take a little while, I don't know if you wanted to hang around or…"

"No thanks I'll… give me a call when the results are in yeah?" John said awkwardly. Now there was nothing more he could do but wait, it was getting harder to keep his emotions at bay, and was rapidly feeling the need for some fresh air.

"Okay well… tell Sherlock I said hi. He hasn't popped in in a while and… well it'd be nice to see him"

"Okay, I will." John quickly assured her, straining not to run from the room in his haste. He walked the halls with military stiffness until he made it outside the hospital, leaning against the wall and taking a few big breaths for composure.

There was no denying it really, no use clinging to the small hope that it had all been coincidence and that Mary hadn't really been unfaithful to him. No, if running around with Sherlock had taught him anything it was to never ignore a coincidence, as they were rare indeed.

And it wouldn't be the first time Mary had lied to him. Had hurt him. Had betrayed him. He felt it as sorely as when he'd found out she'd shot Sherlock; the anger burning in his stomach at the same time as a coldness seizing his heart, making him numb and hyperaware of the situation at the same time.

The question was, had his friend betrayed him too? Had both people he trusted and loved most in the world turned on him together?

In a way, the thought didn't feel so bad. It should. He knew he should want to kill Sherlock if it were the case, and part of him did. But the other part of him… would be relieved. And not only because it would save him from his current predicament, but because the idea of him with Mary was somehow preferable to her with someone else.

Because he had seen the spark between them, hadn't he? Even commented on it, albeit sarcastically as they sat around at Baker Street, calmly discussing how she had shot him then saved him. He had been secretly glad the night Sherlock had come back and Mary had smiled and said 'I like him', and when she had excitedly read the blogs of their time together. After all the girlfriends he'd had who had left because they couldn't tolerate his closeness to Sherlock Holmes, he had been greatly relieved that the one he intended to spend the rest of his life with had not only accepted, but encouraged their friendship. And Sherlock for once had not a bad thing to say about her either. It had seemed perfect.

So if they had given into their mutual interest in one another, at least he knew it was that. At least he knew that the person bedding his wife truly cared about her. Because wasn't that better than the alternative? Someone who could care less about her other than as a warm body at night? And what would that say about him, if she was resorting to sleeping with the postman? He liked to think he could keep his wife satisfied, but if it was some random bloke she'd slept with, what else could it be than that he wasn't? Or the only other option, if it was some long forgotten lover shown up from her past life? She might be considering running away to be with him, but if it was Sherlock, then that wouldn't be an issue, would it?

And that's when it clicked. The same thing that it had taken him months to realize the first time round, but when it did, made his decision so much easier. The fact that he was far more afraid of losing her, or rather _them_, than he was angry at them. And the fact that they would go to such lengths to keep it from him suggested that they felt the same. Oh that didn't mean that he wasn't still angry, but there was a light at the end of the tunnel. He could be mad at them, but he wouldn't have to lose them, and that was a far more unbearable thought than what they had done was.

It all came down to what Molly found. He was almost tempted to go back in and wait in the lab like she'd first suggested, but as it happened, he didn't need to. His phone rang in his pocket and it took him only a few seconds to pull it out and answer, despite almost fumbling with it in his haste.

"Did you get them?" He asked nearly breathlessly, for once not bothering with social niceties as he often scolded Sherlock for, in his desperation to know.

"Um... Hi John. Yeah, I… I got them. Your man it was… it was Sherlock." She said in a small voice, the one John had heard many a time after Sherlock had insulted her. John could almost sympathise with her disappointment, was it not for the wave of emotions that accompanied her news. Despite his previous thoughts that it would be better if it was Sherlock, he was still very angry, and had to take a deep breath to calm himself, almost missing her next words.

"I couldn't identify the woman; there were some cells there, but I couldn't find a match for her DNA on our records."

He wasn't surprised, not with her past. The fact that the records were missing was all the proof he needed.

"Mary… it was Mary." He breathed, not sure why he was telling Molly, but somehow needing to.

"Oh, John. Sherlock didn't send you did he?" Molly replied, all self-pity gone for her voice replaced with genuine empathy.

"No. I just… needed to know." John admitted.

"Of course. Listen if there's anything you need… I mean other than the use of my lab, if you needed to talk to anyone… ever. Not that I'm trying to replace Mary, I just-"

"I know." John assured her. "Thank you. Actually there is one thing you could do for me."

"Anything." Molly prompted him.

John smiled sadly. "Don't give up on Sherlock. I don't know whether this means he's ready for a woman in his life, but if it does I think it should be you, not Mary. Hopefully it won't take him too long to realise that either."

"Are you asking me to distract Sherlock from your wife?" Molly tried to joke, hoping it wasn't too soon. Thankfully John laughed.

"Oh don't you worry, when I'm through with him, he won't need distracting to keep his hands off my wife."

He pulled the phone away from his ear to hang up, but Molly's voice called him back.

"John? Don't you give up on Sherlock either."

"I haven't" John assured her, hanging up the phone and hailing a cab, sending a text to Mary as he climbed in.

_Sherlock's cell, 20 minutes. J x_

"John!" Mary called across the foyer of Scotland Yard, arriving minutes after him as he waited for Lestrade to come down. "What's going on, did you find something?"

"You could say that." He replied, trying to keep his voice level though unable to look her in the eye. Thankfully Lestrade's arrival distracted her from thinking anything of it.

"Well that was quick, you only left just over an hour ago." He said with a hopeful grin, "You'll be wanting to talk to Sherlock, I take it?" He added, grabbing a pair of keys from the desk Sergeant.

"Both of you actually." John clarified, following with Mary to Sherlock's cell. The air was tense with mixed emotions as Lestrade unlocked it, Lestrade hopeful, Mary wary and John determined.

"John? Mary. Well that was quick, news on the case already?" Sherlock asked, watching the three of them file in, an obvious prelude to some either very good or very bad news. John's tense stance said bad, but not so bad that Sherlock could see what was coming.

"Not the case exactly. Your alibi." John said in measured, steady tones. He shifted his weight slightly, only a small give to his emotional state, as Mary behind him paled, and Sherlock resisted the urge to flinch. Only Lestrade seemed apparently unaffected by the sudden mercurial shift in the room's atmosphere. "I'm going to give you one more chance, Sherlock." John continued, his tone getting sharper. "One more chance to tell us – to tell _me_ where you were on Friday night."

Sherlock's eyes flicked to Mary, for her permission. She gave the smallest of nods, and he turned back to John, keeping his eyes on his friend as he spoke for the record to Lestrade.

"On the night of Friday 21st September 2014, I William Sherlock Scott Holmes was at the Watson's residence. Engaging in coitus with Mrs Mary Elizabeth Watson."

Lestrade's jaw dropped. Whatever he had been expecting Sherlock to have been hiding, it hadn't been that. A million questions buzzed round his head, and he had to remind himself that he wasn't here for juicy gossip, but to do his job. Clearing his throat he turned to Mary, "Right then… Mary do you confirm Sherlock's location at that time?" He asked, as professional as possible.

"Yes." She gasped, tears streaming down her face as she stared guiltily at her husband, as though waiting for him to pass sentence on her.

"Right then I'll… I'll go… get things sorted then." Lestrade excused himself awkwardly, leaving the three to do some seriously needed talking.

"John, I-" Mary started as soon as they were alone, but John held up a hand, instantly silencing her. He finally released Sherlock from his accusing glare, dropping his eyes to the floor and taking a big breath before lifting them back to Mary, forcing words he had prepared in the taxi over out of his lips.

"Mary. Am I in any way not adequate, or not fulfilling your needs emotional and sexual needs, as a husband?"

"No!" Mary vehemently answered, her hands fluttering in need to touch him but not certain they would be welcomed. "No of course not, you couldn't be more perfect. I love you, I just… please, you have to understand this isn't about you it's -"

**"**Him." John finished for her, with a firm nod, turning back to Sherlock, who hadn't moved an inch since his confession. "You do realise I'm going to have to hurt you for this, don't you, Sherlock?"

"I know an alley in Peckham with no CCTV and neighbours who will turn a blind eye to any kind of violence." Sherlock answered immediately, seeming more welcoming of John's anger than he had his help earlier in the day. "Though I would prefer it if we waited until after the current cased is solved, as chasing a criminal with broken ribs might be problematic."

John couldn't help the laugh that escaped him, his anger somewhat disarmed by Sherlock's answer. He shook his head, trying to clear it as he looked back and forth between his wife and his best friend.

"Okay... okay." He sighed. "I just… I'm still very mad at you both, and if anything like this ever happens again-"

"It won't." Sherlock and Mary answered simultaneously and earnestly.

"I should think not, but… if it does I don't know if I'll be as able to forgive either of you, but as it stands… I'm already halfway there so… yeah, just don't pull anything like this again. And y'know, some grovelling in the form of housework and gifts wouldn't go amiss either."

"Dibs on the jumper." Sherlock shot at Mary as he stood from his bench, referring to a jumper he'd seen John admiring and pointed out to her as a potential Christmas present.

"Already in the wardrobe. Bought it yesterday" Mary replied with a smirk.

"Great way to tip him off that something's up" Sherlock rolled his eyes.

"Actually I didn't get that far, the empty bottle of wine and changed sheets were far more suspect." John said, unable to prevent himself in gloating slightly at his detective skills.

"Well done, John, you've obviously learned more than you usually let on." Sherlock backhandedly commended him. "But you'd need more evidence than that before you'd believe it. I suppose I should be expecting another slap from a certain pathologist next time I need to visit the morgue."

"I'd recommend accepting her invitation to coffee next time." John suggested with mock innocence.

A timid knock on the door interrupted their banter, and Lestrade warily stuck his head in, clearly expecting to be interrupting far worse.

"Um, just letting you know everything's squared our end if… things are cool here?"

"Right, I'd better get the Mrs home then. Have fun figuring the rest out Sherlock, I'll see you in Peckham about 7?" John said with exaggerated casualness, enjoying the confusion on Greg's face. Sherlock smirked in return, waving them off as he turned back to Lestrade.

"All good here Detective, now where are those case files? Can't be sitting around in a cell all day when there's a case to solve!"

_AN: I Know, ridiculously cheesy ending. It was that or trail off pathetically. _

_So thats all folks, thanks for reading and for the follows and favorites and reviews, I really wasn't sure if anyone would be interested in this, so I am glad some people liked it. And apologies to those who didn't/were hoping it was something else going on, as previously stated, I know the concept was out of character, but the the plot bunnies were just eating away at me._

_Again thanks for reading :)_


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